Rec. zool. Surv. India: Vol. 120(3)/247–250, 2020 ISSN (Online) : 2581-8686 DOI: 10.26515/rzsi/v120/i3/2020/143326 ISSN (Print) : 0375-1511 A report on Ingerana borealis (Annandale, 1912) (Anura: Dicroglossidae) from inside a cave Bhaskar Saikia* and Uttam Saikia Zoological Survey of India, North Eastern Regional Centre, Risa Colony, Shillong, Meghalaya, India Email: [email protected] Abstract The trickling stream dwelling frog Ingerana borealis (Annandale, 1912) Based on voucher specimens collected in 2006, 2019 and 2020 from inside this cave, a viable population of this species is found to thrive within the cave ecosystem of Krem is reported from a cave habitat for the first time. Lymput, located in East Khasi Hills of Meghalaya. A note on the altitudinal distribution and the habitats of this species is also added. Keywords: Altitudinal Distribution, Cave Frog, Cave Lymput, Khasi Hills, Krem, Meghalaya Introduction Krem (=Cave) Lymput located in the Nongjri Elaka of East Khasi Hills, Meghalaya, India. Krem Lymput [25.32555 N; The Trickle frog Ingerana borealis was described by 91.86138 E; 20 m asl] is a well known limestone cave in Annandale 1912 based on specimens collected under East Khasi Hills of Meghalaya with magnificent calcite stones in a stream from Rotung and 3 miles south of formations and spacious chambers (Figure 1). The cave, Yembung in the Siang Valley of Arunachal Pradesh. Now, although not fully explored, is estimated to spread over a the frog is reported to have a wide distribution range from few kilometres with a number of passages. the south-eastern Tibet, eastern Nepal, Bhutan, north- Two female specimens of this species (ZSI V/A/ eastern India, Bangladesh to north-western Myanmar ERS/705) were collected in January, 2006 from about (Frost, 2019). For a long time, there was no further 200 m inside the cave by Ilona Jacinta Kharkongor. information on the occurrence of this species in India, Another female specimen (ZSI V/A/NERC/1456; until Pawar & Birand (2001) rediscovered it from Nameri Figure 2) was collected in mid March 2019 from about National Park in Assam and Pakhui Wildlife Sanctuary in the same location by Uttam Saikia. Five more specimens Arunachal Pradesh. Thereafter, this frog has been reported (ZSI V/A/NERC/1539; Figure 3) were collected recently from a number of localities in Nagaland, Meghalaya, in January 2020 from the cave within a distance of 200- Manipur and Mizoram (Ao et al., 2003; Mathew & Sen, 1000 m from the cave entrance by Ilona Jacinta Kharkongor 2003; Devi & Shamungou, 2006; Sailo et al., 2009). (Chettri and Bhaskar Saikia. Some more individuals of this species et al. 2011) mentioned this species from Sikkim although were encountered along this stretch though not collected. it was not supported by any vouchers. During our visit in mid March of 2019, the cave had a few Though available natural history information on this small pools with waist deep water and water filled tunnels species remains poor, it is known to be associated with suggesting extensive flooding during rainy season. While, small still or moving water bodies in moist tropical forest during the visits in January, 2006 and 2020, the cave was (Lau et al., 2004). In the present communication, we relatively dry with some water puddles and certain muddy report the occurrence of this species from inside a cave in stretches and no flowing water was observed. East Khasi Hills of Meghalaya which is an unusual habitat All the individuals were collected or spotted while for this frog. surveying for cavernicole fauna. They were found in shallow or moderately deep puddles (Figure 4) on Material and Methods the cave floor resulting from flood water erosions. The present report is based on eight specimens of Apparently, the retained water in such puddles during the I. borealis collected over a period of 14 years from inside of dry period served as a suitable hibernaculum for these * Author for correspondence Article Received on: 29.03.2019 Accepted on: 15.03.2020 A report on Ingerana borealis (Annandale, 1912) ... Figure 1. A view of Krem Lymput (at about 500 m Figure 3. Ingerana borealis inside Krem Lymput, col- inside), East Khasi Hills, Meghalaya, India lected on 9 January, 2020 (Photo: Bhaskar (Photo: Ilona J Kharkongor). Saikia). Figure 2. Ingerana borealis inside Krem Lymput, collect- ed on 19 March, 2019 (Photo: Uttam Saikia). frogs. The frogs when disturbed jumped out of water (or goes deep in the puddles) and after a while again enter the puddle suggesting their familiarity with the location. Interestingly, all these puddles (varying sizes of 30-100 cm diameter) were observed to hold only single individual of this frog. A few basic morphometrics of the specimens were taken using a MitutoyoTM digital calliper and the date is presented in Table 1. The specimens were identified Figure 4. Some cave holes harbouring the frogs are following Sailo et al. (2009). quite deep (Photo: Bhaskar Saikia). Results longer than eye diameter; nostril equidistant, inter- narial distance larger than inter-orbital distance; Small sized frogs (snout vent length: 21.6-32.6 mm), a pointed tooth-like projection prominent on the lower with stout body; head wider than long; snout rounded, jaw; tongue notched; vomerine teeth absent; tympanum 248 Vol 120(3) | 2020 | www.recordsofzsi.com Zoological Survey of India Bhaskar Saikia and Uttam Saikia Table 1. Basic morphometrics of I. borealis specimens collected from Krem Lymput, Meghalaya, India Characters Measurements (in mm) Registration Number V/A/ERS/705 V/A/NERC /456 V/A/NERC/1539 Date of Collection 19.01.2006 21.03.2019 09.01.2020 Sex ♀ ♀ ♀ ♀ ♀ ♂ ♂ ♂ Snout Vent length 26.4 27.1 25.6 28.3 32.6 22.4 21.6 26.1 Head Length 7.8 8.0 8.1 7.2 9.3 7.0 6.4 8.1 Head Width 9.1 9.1 9.6 9.4 10.9 8.1 7.9 9.4 Mandible Nostril distance 6.2 6.2 6.1 5.8 6.8 4.3 4.5 6.0 Inter-narial distance 3.1 3.4 3.1 3.4 4.1 2.4 2.5 3.0 Distance from eye to nostril 1.9 2.3 2.1 2.3 2.5 1.8 1.6 2.0 Distance from snout tip to nostril 1.9 2.2 2.1 2.3 2.4 1.8 1.6 2.0 Eye diameter 3.2 3.3 3.2 3.3 3.5 3.1 2.9 3.1 Snout length 3.4 3.6 3.6 3.8 4.0 3.4 3.2 3.3 Tympanum Diameter 2.3 2.1 1.8 2.1 2.4 2.2 2.1 2.1 Minimum distance between the 2.4 2.6 2.5 2.5 2.7 2.2 2.1 2.4 upper eyelids Maximum width of the upper 2.4 2.4 2.2 2.4 2.9 2.1 2.0 2.3 eyelid Femur Length 13.6 12.6 13.9 15.1 16.9 12.1 11.4 13.7 Tibia Length 14.5 14.8 14.3 15.8 17.1 12.8 12.2 14.0 Length of tarsus and foot 18.9 19.9 19.7 21.8 24.4 17.3 16.2 18.9 Foot length 13.1 13.7 12.4 14.8 16.1 11.4 10.9 12.9 round, indistinct; supra-tympanic fold distinct; dorsum collected from stream edges inside moist evergreen forest finely reticulated; ventrum smooth; forearm thin; finger (Das et al., 2016). In other parts of its range too, this I < II; finger tips dilated; hind limbs strong, tibia slightly species was collected from under the rocks, on the sides longer than femur; toes webbing almost complete; of slow moving streams (Wogan et al., 2008; Mahony inner metatarsal tubercles not prominent, short; outer et al., 2009; Sarker & Lovlu, 2014). On two occasions, one metatarsal tubercle absent; dorsal colour light brown, of the authors (BS) had made collections of I. borealis spotted with dark grey markings; faint inter-orbital band from Umkiang in East Jaintia Hills, Meghalaya and and an inverted chevron mark; limbs banded. Jengging in Upper Siang, Arunachal Pradesh (near the type locality) from beneath the rocks by the sides of hill Discussion streams, in conformity with the observations of other researchers. Ingerana borealis was described based on 8 specimens Occurrence of frogs near the cave entrance is not collected from Rotung and Yembung of Abor Hills uncommon, especially of frogs belonging to genera (=Siang Valley) of Arunachal Pradesh (Annandale, Minervarya and Amolops. However, finding this frog 1912). This species usually live among litter and rubble deep inside a cave, which so far known to be associated in trickling and seeping streams in and around forest with forest streams, is interesting. Hasan et al. (2011) (Pawar & Birand, 2001). In Mizoram, specimens were while reporting this species from Cox’s Bazaar district of mostly collected from leaf litter and boulders of cascading Bangladesh had collected two specimens of this species or trickling streams inside forests (Sailo et al., 2009). In from partially decomposed leaf litter near a stream in front Royal Manas National Park, Bhutan, this species was of a cave. But, the present specimens were found about Vol 120(3) | 2020 | www.recordsofzsi.com Zoological Survey of India 249 A report on Ingerana borealis (Annandale, 1912) ... 200-1000 m deep inside the cave which is a significant Presently reported specimens were collected from distance for a frog of this size. Besides, the forest around an altitude of about 20-50 m, but in Bhutan, specimens the cave entrance is replaced by beetle nut plantations and are known from altitude of 1000 m (Sailo et al., 2009) there is no stream flowing close by from where it could indicating its broad altitudinal range.